Wierd Idle

[Mikeyi]

Hello I just purchased a 1983 Chev k20. It is a frame off restoration. It has a new 350 crate engine with 1000km on it.

The problem i am having is when i go from drive to park it has a high idle. When i shut it off it sputters like its still getting more fuel. The guy i bought it from says he had issues with the electronic choke. Would a choke do this or? From what i read it could be a timing issue? The gas peddle is also very sloppy with play i got to lift up on it sometimes to let the throttle off. I do the same when its in park but doesn't solve the high idle.

Any information would be great!

I dunno if i am allowed to post pictures here... but here is a few of the truck.

[VileZambonie]

Nice truck. Would look better with chrome bezels with that grille.

How about some pics of your setup under the hood and some details about your engine?

Engine specs, carburetor, ignition system etc

[roundhouse]

The choke may be causing the high idle

Also if you shut it off while it's still in drive it wont sputter



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[Irish_Alley]

check the throttle return spring on the carb

[Mikeyi]

So i checked the throttle/accelerator cable. It almost looks like its over sized there is almost a loop in the cable.
It's also chaffing/fretting and exposed the cable through the plastic.

I search for a replacement cable and it says its 24 inches about the same size as the other cable.

[bd]

Begin by replacing that cable.  Throttle cables are long by design to allow for engine movement and prevent full throttle jamming in the event of a collision.  What carburetor are you running?

[Mikeyi]

I just purchased the truck last week. I was told it was a quad carb it was rebuilt and tuned by a performance shop.

[Irish_Alley]

yeah sometimes it can be worn and get hung up or the spring isnt puling it back. is there a lot of resistance when you press the pedal? if you look up a accelerator cable for lets say a 77 305 with a 2 barrel it will be about a 1" shorter. but there shouldnt be anything wrong with the length of your cable now

[Silver_Bullet85]

Mikey, I had the same issue with my crate 383, my gas pedal was pretty sloppy and it would stick quite a bit, especially at low rpm. Try adjusting the idle speed on the carb if it's consistently idling high, but if it's just sticking then any auto parts store should have some throttle return springs for pretty cheap. If the one you have is old it could've lost some of its bounce, I ended up doing both and I have very good response and return on my throttle now.


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[Silver_Bullet85]

The positioning and angle of the cable makes a difference too so check for restrictions and bends that could be grabbing the cable.


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[mike657894]

i didn't read the responses but my exp tells me you need to go through your vacuum set up look for leaks. you not shutting off is because your too rich and carbon build up is igniting your fuel after you shut off. lean it out a tad and check for leaks. cracked and loose vac lines

[Mikeyi]

Hey Mike you nailed it.

 I just got back from the mechanic said the vacuum was set up wrong on the carb. He also changed the return spring location. The pedal is a bit stiff now returns great though.

Thanks for the responses